Re: Streamlining (or textured fill topography)

["Robert Dahni" <r.dahni(at)bom.gov.au>]

"Martin Schultz" <martin.schultz@dkrz.de> wrote in message
3AC30420.2F9A10E4@dkrz.de">news:3AC30420.2F9A10E4@dkrz.de...
> Robert Dahni wrote:
> >
> > I am currently looking at IDL 's ability to automatically plot
"streamlines"
> > from the
> > wind field (u,v components) from a meteorologist's point of view.
> >
> > I have used the procedures PARTICLE_TRACE, PLOTS and ARROW with success
> > (IDL V5.3 on Windows).
> >
> > Take a look at this example
> > http://www.metvis.com.au/graphics/streamline.jpg.land and seafloor
topography data sets
> >
> > Robert Dahni
> > Meteorologist, IDL Programmer
> > Bureau of Meteorology, Melbourne, AUSTRALIA
> > r.dahni@bom.gov.au
>
> Hi Robert,
>
>     that looks really nice. Where did you get this "background" image
> from? Is this something that's publically available? Does it cover the
> whole earth and can you zoom in at will? This looks far nicer than the
> plain IDL map background...

The background image is the result of a textured fill of a subset of GTOPO30
global topography. I have been able to "zoom in at will" in another GUI
application, by "re-calculating" the textured fill from the topography data.

Links to global coastlines, land and seafloor topography data sets can be
found at www.metvis.com.au/idl/idl_resources.html including the publically
available GTOPO30 topography. But beware, it is a large global data set and
we have had to break up the tiles into more manageble smaller ones, and
extract a region of interest at a specified resolution..

If you are interested in a sample (small) GTOPO30 topography data set, the
textured fill image (as a GIF file) and the IDL code used to produce the
image, please e-mail me (r.dahni@bom.gov.au) with the latitude and longitude
limits of your region of interest (please don't ask for near the poles?).

I've been a lurker of this valuable newsgroup for many years, and it's time
I started making a greater contribution for the benefit of this vast IDL
community.

Robert Dahni
Meteorologist, IDL Programmer
Bureau of Meteorology, Melbourne, AUSTRALIA
r.dahni@bom.gov.au